U.S. patent application number 17/294725 was filed with the patent office on 2022-01-13 for work machine with sensor enabled user control.
This patent application is currently assigned to Caterpillar Inc.. The applicant listed for this patent is Caterpillar Inc.. Invention is credited to Alessandro ROSSI.
Application Number | 20220010531 17/294725 |
Document ID | / |
Family ID | |
Filed Date | 2022-01-13 |
United States Patent
Application |
20220010531 |
Kind Code |
A1 |
ROSSI; Alessandro |
January 13, 2022 |
WORK MACHINE WITH SENSOR ENABLED USER CONTROL
Abstract
A work machine comprises an armrest and a user control operable
by the user to control tool or machine functions when the user's
arm rests on the armrest. An armrest sensor is configured to sense
the presence of the user's arm and to disable the control when the
user's arm is removed from the armrest. The control may be mounted
on the armrest and the armrest movable between enabling and
disabling positions by the weight of the user's arm. A seat sensor
may be configured to disable the control when the user leaves the
seated position.
Inventors: |
ROSSI; Alessandro; (Seaham,
GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Caterpillar Inc. |
Peoria |
IL |
US |
|
|
Assignee: |
Caterpillar Inc.
Peoria
IL
|
Appl. No.: |
17/294725 |
Filed: |
November 12, 2019 |
PCT Filed: |
November 12, 2019 |
PCT NO: |
PCT/US2019/060832 |
371 Date: |
May 18, 2021 |
International
Class: |
E02F 9/24 20060101
E02F009/24; B60W 50/12 20060101 B60W050/12; B60N 2/00 20060101
B60N002/00; B60N 2/75 20060101 B60N002/75; E02F 9/20 20060101
E02F009/20 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 19, 2018 |
GB |
1818809.4 |
Claims
1. A work machine including: a tool; a seat; an armrest; a control
system, the control system including a control operable by a left
or right hand of an operator to control the work machine or the
tool when the operator is seated in the seat and a corresponding,
left or right arm of the operator is resting on the armrest; and an
armrest sensor, the armrest sensor configured to operate the
control system: to enable the control responsive to sensing
application of the operator's arm to the armrest, and to disable
the control responsive to sensing removal of the operator's arm
from the armrest.
2. A work machine according to claim 1, wherein the armrest sensor
is configured to operate the control system: to enable the control
responsive to sensing application of force to the armrest, and to
disable the control responsive to sensing relief of said force from
the armrest.
3. The work machine according to claim 2, wherein the armrest, or
an upper surface of the armrest, is downwardly movable by said
application of force against an upwardly directed restoring force
from an upward, disabling position to a downward, enabling
position, and is upwardly movable by the restoring force from the
enabling to the disabling position, and the armrest sensor is
configured to sense said application and relief of force by upward
and downward movement of the armrest between the disabling and
enabling positions.
4. The A work machine according to claim 3, wherein the control is
mounted on the armrest.
5. The A work machine according to claim 1, wherein the armrest
sensor is configured to operate the control system to enable the
control responsive to sensing application of the operator's arm in
any of at least two alternative positions to the armrest.
6. The work machine according to claim 1, further including a seat
sensor configured to operate the control system: to enable the
control responsive to sensing presence of the operator in a seated
position on the seat, and to disable the control responsive to
sensing absence of the operator from the seated position.
7. The A work machine according to claim 6, wherein the seat sensor
is configured to operate the control system: to disable the control
responsive to sensing absence of the operator from the seated
position for a time period longer than a delay interval, and not to
disable the control responsive to sensing absence of the operator
from the seated position for a time period shorter than the delay
interval.
8. The work machine according to claim 7, wherein the armrest
sensor is configured to operate the control system to disable the
control, either immediately or within a time period shorter than
the delay interval, responsive to sensing removal of the operator's
arm from the armrest.
9. A method of controlling a work machine, the work machine
including: a tool, a seat, an armrest, and a control system, the
control system including a control operable by a left or right hand
of an operator to control the work machine or the tool when the
operator is seated in the seat and a corresponding, left or right
arm of the operator is resting on the armrest; the method
comprising operating the control system, by an armrest sensor: to
enable the control responsive to sensing application of the
operator's arm to the armrest, and to disable the control
responsive to sensing removal of the operator's arm from the
armrest.
Description
TECHNICAL FIELD
[0001] This disclosure relates to work machines having a user
control which is selectively enabled and disabled by one or more
sensors.
BACKGROUND
[0002] In this specification, a work machine means a mobile,
self-contained apparatus that is operable by an operator seated on
or in the apparatus to manipulate a tool. Typically a work machine
is configured as a steerable land vehicle mounted on wheels or
tracks, although non-vehicular types are known. A tool means a work
implement which is mounted on a work machine and operable to carry
out work on objects or materials in the vicinity of the work
machine. In many work machines the tool is movable relative to the
body of the work machine, and many such tools will include parts
that are movable relative to each other.
[0003] Work machines often have hydraulic power transmission
systems and include excavators, backhoe loaders, wheel loaders,
draglines, knuckleboom loaders, grading or surfacing machines and
many other types. The tool may comprise a bucket for digging or
moving loose material, a hydraulic breaker, a grab, a scraper or
any other useful work implement.
[0004] The tool, the motion of the work machine over the ground
surface, or combinations of these functions are controllable by one
or more user controls, often configured as a lever or joystick and
mounted on or proximate an armrest of the seat. In many work
machines, one or more sensors will be arranged to selectively
disable the controls in order to guard against inadvertent
operation of the tool.
[0005] Such sensors may be arranged to detect an operation that
necessarily occurs before or after use of the tool, such as moving
a feature of the cabin from a position that prevents the operator
from leaving the seat, to a position that allows the operator to
leave the seat.
[0006] For example, WO2008036207 (A1) discloses a work machine
having a joystick which is selectively enabled and disabled by
rotation of an armrest in vertical and horizontal planes.
[0007] Alternatively, sensors may be arranged to detect the
presence or position of the operator directly. This ensures that
the control cannot be enabled when the operator is not present. In
practice however, some users can find it uncomfortable to maintain
the correct hand or body position to activate such sensors so as to
maintain the control in an enabled condition for the duration of a
work cycle.
[0008] U.S. Pat. No. 7,121,608 B2 discloses a work machine having a
swivelling seat and controls that are selectively enabled and
disabled depending on the position of the seat by different sensors
for sensing the foot, leg, hand, or seated position of the
operator.
[0009] In a different technical field, U.S. Pat. No. 8,775,001 B2
discloses a wheelchair in which a joystick control is activated by
a sensor mounted in the armrest and operable by a detectable
component worn by the user when the operator's hand, wrist or arm
is in a normal operating position.
SUMMARY
[0010] In a first aspect of the present disclosure there is
provided a work machine including a tool, a seat, an armrest, a
control system, and an armrest sensor. The control system includes
a control operable by a left or right hand of an operator to
control the work machine or the tool when the operator is seated in
the seat and a corresponding, left or right arm of the operator is
resting on the armrest. The armrest sensor is configured to operate
the control system: to enable the control responsive to sensing
application of the operator's arm to the armrest, and to disable
the control responsive to sensing removal of the operator's arm
from the armrest.
[0011] In another aspect, the disclosure provides a method
comprising operating the control system, by an armrest sensor: to
enable the control responsive to sensing application of the
operator's arm to the armrest, and to disable the control
responsive to sensing removal of the operator's arm from the
armrest.
[0012] The control may be mounted on the armrest.
[0013] The armrest sensor may be configured to operate the control
system to enable the control responsive to sensing application of
the operator's arm in any of at least two alternative positions to
the armrest.
[0014] The armrest sensor may be configured to operate the control
system: to enable the control responsive to sensing application of
force to the armrest, and to disable the control responsive to
sensing relief of said force from the armrest.
[0015] For example, the armrest, or an upper surface of the
armrest, may be downwardly movable by said application of force
against an upwardly directed restoring force from an upward,
disabling position to a downward, enabling position, and upwardly
movable by the restoring force from the enabling to the disabling
position, the armrest sensor being configured to sense said
application and relief of force by upward and downward movement of
the armrest between the disabling and enabling positions.
[0016] The work machine may further include a seat sensor
configured to operate the control system: to enable the control
responsive to sensing presence of the operator in a seated position
on the seat, and to disable the control responsive to sensing
absence of the operator from the seated position.
[0017] The seat sensor may be configured to operate the control
system: to disable the control responsive to sensing absence of the
operator from the seated position for a time period longer than a
delay interval, and not to disable the control responsive to
sensing absence of the operator from the seated position for a time
period shorter than the delay interval.
[0018] In this case, the armrest sensor may be configured to
operate the control system to disable the control, either
immediately or within a time period shorter than the delay
interval, responsive to sensing removal of the operator's arm from
the armrest.
[0019] The above mentioned optional features may be provided
individually or in any desired combination.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Further features and advantages will become evident from the
illustrative embodiments which will now be described, purely by way
of example and without limitation to the scope of the claims, and
with reference to the accompanying drawings, in which:
[0021] FIG. 1 shows a work machine in accordance with a first
embodiment;
[0022] FIG. 2 shows a control system of the work machine;
[0023] FIG. 3 shows a seat of the work machine;
[0024] FIG. 4 shows the seat in use; and
[0025] FIG. 5 shows the logic of the control system.
[0026] Reference numerals appearing in more than one of the figures
indicate the same or corresponding features in each of them.
DETAILED DESCRIPTION
[0027] Referring to FIGS. 1-4, a vehicular work machine 1 includes
tools 2, 3 operable by a hydraulic power transmission system (not
shown) which in turn is controlled by a valve control unit 11 of a
control system 10. The machine 1 has a cabin 4 for the operator
which includes a seat 20 with an armrest 21.
[0028] The control system 10 includes a control 12 which is
operable by the right hand of an operator 5 to control the work
machine or one or more of the tools when the operator is seated in
the seat and the right arm of the operator is resting on the
armrest 21, as shown in FIG. 4. In the illustrated embodiment, the
control 12 is configured as a joystick with various additional
switches and functional elements, and is mounted on a distal end of
the armrest 21.
[0029] The armrest 21 includes an armrest sensor 22, which is
configured to sense the application of the operator's arm to the
armrest and the removal of the operator's arm from the armrest.
[0030] The armrest sensor may be configured to detect the force or
pressure applied to the armrest by the weight of the operator's arm
resting upon it, or otherwise to detect the presence of the
operator's arm by any suitable contact or non-contact sensing
technology, or a combination of different technologies.
[0031] The armrest sensor 22 is configured to operate the control
system 10 to enable the control 12 responsive to sensing the
application of the operator's arm to the armrest, and to disable
the control 12 responsive to sensing the removal of the operator's
arm from the armrest. It is to be understood that enabling and
disabling the control means selectively arranging for operator
input to the control (e.g. manipulation of the joystick or
operation of the switches) to cause movement or other functional
output of the tool or machine in the enabled condition, but not in
the disabled condition. For example, the control system 10 may
interrupt output signals from the control 12 in the disabled
condition, and re-establish those signals in the enabled
condition.
[0032] In the illustrated embodiment, the control 12 is configured
in the enabled condition to send signals via the control system 10
to the hydraulic valve control unit 11 so as to control movement of
the tools 2, 3 and/or vehicle wheels responsive to moving the
joystick and switches. When the control 12 is disabled, the signals
are interrupted so that operator input to the control 12 has no
effect on the operation of the vehicle and its tools.
[0033] In the illustrated embodiment, the armrest sensor 22 is
configured to operate the control system 10 to enable the control
12 responsive to sensing application of downward force to the
armrest 21 by the weight of the operator's arm resting upon it, and
to disable the control 12 responsive to sensing the relief of the
downward force from the armrest 21 when the operator lifts that arm
away from the armrest.
[0034] To accomplish this, an upper surface of the armrest or, as
shown, the entire armrest 21 may be downwardly movable by the
application of said weight or downward force against an upwardly
directed restoring force supplied for example by a return spring 23
from an upward, disabling position (21', FIG. 3) to a downward,
enabling position (21'', FIG. 3). The armrest is upwardly movable
by the restoring force which returns it from the enabling position
21'' to the disabling position 21'.
[0035] The armrest sensor 22 is configured to sense this
application and relief of force by the upward and downward movement
of the armrest 21 about its pivot axis 24 between the disabling and
enabling positions, and may be configured for example as a simple,
mechanically or magnetically operated switch or equivalent device
as shown.
[0036] It will be understood of course that the relief of force, or
the removal of the operator's arm, is sensed simply as that
condition in which the force applied by the operator's arm, or the
presence of the operator's arm, is no longer sensed. Thus, the
disabling position 21' of the armrest need not be clearly defined;
rather, the armrest sensor 22 may supply an output signal
corresponding to the disabling position, at that point when the
armrest 21 is sensed not to be in the enabling position 21''.
[0037] Where the control 12 is mounted on the armrest, for example,
at a distal end of the armrest as shown, the operator may raise
their arm from the armrest 21 without removing their hand from the
control 12 so that the downward force applied by the operator via
the control 12 to the armrest will maintain the armrest in the
enabling position 21''. In this way the operator is able to shift
the position of their arm without interrupting their work. However,
if the operator releases the control, then lifting the arm from the
armrest 21 will cause the spring 23 to move the armrest upwardly to
the disabling position 21'.
[0038] By configuring the entire armrest to move between the
enabling and disabling positions, it is possible for the operator
to move their arm position, for example, to rest their elbow or
their wrist alternatively on the armrest. Thus, the armrest sensor
22 is configured to enable the control 12 responsive to sensing
application of the operator's arm in any of at least two
alternative positions 40, 41 to the armrest.
[0039] In the illustrated embodiment, a seat sensor 25 is provided
for sensing the presence of the operator in a seated position on
the seat as shown in FIG. 3, and the absence of the operator from
the seated position as shown in FIG. 4. It will be understood that
the seated position is sensed as that position in which the
operator's weight is (principally) supported by the upwardly facing
seat surface 26, and the absence of the operator from the seated
position is sensed as that condition in which the operator's weight
is no longer supported thereby.
[0040] The seat sensor may comprise a pressure sensor, a proximity
sensor or any other suitable arrangement that detects when the
operator is seated. In the illustrated embodiment the seat sensor
25 is integrated into the seat 20 as a simple, mechanically or
magnetically operated switch or equivalent device, which detects
the presence of the operator in the seated position by the movement
of a pressure pad 27 which is upwardly biased to a rest position by
a return spring 28 and moved downwardly by the weight of the
operator on the seat surface 26. Since the operator's weight
applies a substantial force to the pad 27 the seat sensor can
distinguish with high reliability between the seated position and
the absence of the operator from the seated position.
[0041] The seat sensor 25 is configured to operate the control
system 10 to enable the control 12 responsive to sensing the
presence of the operator in a seated position on the seat (FIG. 3),
and to disable the control 12 responsive to sensing the absence of
the operator from the seated position (FIG. 4). Optionally, the
seat sensor 25 may be configured to operate the control system 10
to disable the control 12 responsive to sensing the absence of the
operator from the seated position for a time period longer than a
delay interval, but not to disable the control 12 responsive to
sensing the absence of the operator from the seated position for a
time period shorter than the delay interval. The control system 10
may include a timer 13 for this purpose along with a processor,
memory, and software for implementing the control logic as known in
the art.
[0042] A short delay interval of a few seconds, for example, from
about 1 second to about 15 seconds, particularly from about 2
seconds to about 10 seconds, may be selected to allow enough time
for the operator to shift their position in the seat or to
momentarily scan the immediate environment of the work machine
before settling back into the seat. For example, a delay interval
of about 5 seconds may be suitable.
[0043] Further optionally, the armrest sensor 22 may be configured
to operate the control system 10 to disable the control 12, either
immediately or within a time period shorter than the delay
interval, responsive to sensing removal of the operator's arm from
the armrest 21.
[0044] FIG. 5 illustrates one simplified, non-limiting example
showing how these functions may be combined in a logical sequence
which can be run iteratively from "Start" to "End" at any desired
frequency, with "Y" and "N" representing "Yes" and "No"
respectively. With respect to the decision point: "enabling
position?", "Y" and "N" represent the armrest sensor 22 outputs,
respectively in the enabling and disabling positions of the armrest
21. With respect to the decision point: "seated position?", "Y" and
"N" represent the seat sensor 25 outputs, respectively for the
sensed presence or absence of the operator with respect to the
seated position.
[0045] The armrest sensor 22 and seat sensor 25 output signals are
combined in a Boolean "AND" function 30 to enable the control 12,
and are configured in effect as a Boolean "OR" function to disable
the control 12.
INDUSTRIAL APPLICABILITY
[0046] It is known that the operator of a work machine will make
many slight changes in their body position during the course of
their work shift in order to remain comfortable and avoid fatigue.
It is found however that where an armrest is provided to support
the operator's left or right arm during operation of the control by
the corresponding, left or right hand (i.e. the hand of the same
arm that rests on the armrest), the operator will tend to maintain
that arm on the armrest at all times when operating the control for
the duration of the work shift.
[0047] Thus, the presence of the operator's arm on the armrest can
be used as a reliable indicator of the presence of the operator in
the working position, without imposing any unnecessary constraint
on the normal movements of the operator in the seat.
[0048] This ensures that the control is enabled only when the
operator is in the working position, while avoiding the fatigue
that is often experienced with hand position sensors mounted on the
control itself, or with sensors that impose positional constraints
on other aspects of the operator's body position which the operator
would otherwise wish to adjust for comfort during their shift.
[0049] In each of its embodiments, the armrest sensor may be
configured to operate the control system to enable the control
responsive to sensing application of the operator's arm in any of
at least two alternative positions to the armrest. For example, the
operator may rest the arm on the armrest alternatively at the wrist
or the elbow. The alternative arm positions provide further freedom
of movement in the seat so as to more effectively observe the
operation of the tool as well as maintaining operator comfort.
[0050] This may be achieved by arranging for the armrest sensor to
operate responsive to sensing application of pressure (particularly
downward pressure) to the armrest, wherein said pressure may be
applied anywhere on the armrest. Optionally, by mounting the
control on the armrest, the pressure may be applied alternatively
to the control itself and, via the control, to the armrest,
providing yet further freedom of movement for the operator.
[0051] One way to achieve this is by arranging for the whole or a
substantial part of the armrest (optionally, including the control)
to be movable against a restoring force between an upward, disabled
position and a downward, enabled position, as described with
reference to the illustrated embodiment.
[0052] Alternatively, it could be achieved for example by one or
more proximity sensors suitably arranged in the armrest to enable
the control responsive to sensing the presence of the operator's
arm in any of the alternative positions.
[0053] By combining the armrest sensor with a seat sensor, it is
possible to configure the armrest sensor to provide still greater
freedom of movement for the operator (for example, by reducing the
threshold force required to be applied to the armrest to enable the
control, or increasing the surface area over which the presence of
the operator's arm will be detected), without incurring an
increased risk of inadvertent operation. The seat sensor disables
the control when the operator is absent from the seated position,
so that both the seat sensor and the armrest sensor must be in the
enabled condition in order to enable the control.
[0054] Optionally, by configuring the seat sensor to disable the
control only responsive to sensing absence of the operator from the
seated position for a time period longer than a predefined delay
interval, the operator is afforded greater freedom of movement to
briefly shift position in the seat or to move to check the
environment close to the machine body, without compromising the
safety afforded by the armrest sensor.
[0055] By configuring the armrest sensor to disable the control,
either immediately on sensing the absence of the operator's arm or
within a time period shorter than the seat sensor delay interval,
the sensors in combination may discriminate more quickly between
the situation where the operator finishes work with the tool and
stands up to do something else or leave the cabin, and the
situation where the operator moves briefly in the seat while
continuing to manipulate the tool.
[0056] In summary, a work machine comprises an armrest and a user
control operable by the user to control tool or machine functions
when the user's arm rests on the armrest. An armrest sensor is
configured to sense the presence of the user's arm and to disable
the control when the user's arm is removed from the armrest. The
control may be mounted on the armrest and the armrest movable
between enabling and disabling positions by the weight of the
user's arm. A seat sensor may be configured to disable the control
when the user leaves the seated position.
[0057] In each of its embodiments, the armrest sensor may be
combined with other safety features as known in the art. For
example, the armrest including the armrest sensor may be manually
movable, or further movable, between different rest positions as
known in the art to provide access for the operator to enter and
leave the seat and/or to provide an additional safety function by
disabling the control in one rest position (representing the
non-use condition) and enabling the control (subject of course to
the operation of the armrest sensor and, where fitted, the seat
sensor) in the other rest position.
[0058] So for example, where the armrest sensor is activated by
movement of the armrest, the armrest may be movable from a first
(inactive) rest position to a second (active) rest position,
wherein a further safety sensor is arranged to disable the control
responsive to sensing the first rest position of the armrest, and
then further movable against a restoring force from the second rest
position (in which the armrest sensor disables the control) to the
enabled position in which the armrest sensor enables the
control.
[0059] The armrest may be mounted on a back or other structural
component of the seat, for example as illustrated, or alternatively
on another part of the structure of the work machine proximate the
other seat components. The armrest and the other seat components
may be fixed or movable relative to each other. In each case
however, the armrest is located in a position to support the
operator's arm when the operator is in the seated position and the
operator is operating the control with the hand of that same
arm.
[0060] The control may be mounted on the armrest or proximate the
armrest.
[0061] In alternative embodiments, either or each of the armrest
sensor and seat sensor may comprise one or more sensors based on
any suitable contact or non-contact sensing technology or, for
better performance, combining more than one such technology,
including sensors operable by force or pressure or movement and
proximity sensors for detecting solid objects as well known in
various applications.
[0062] The control may be configured as a joystick, lever,
switches, touch screen or any other user interface for manipulating
the tool or controlling the movement of the work machine over the
ground (e.g. as a secondary steering system for off-road use), or
combinations thereof.
[0063] Many further adaptations are possible within the scope of
the claims.
[0064] In the claims, reference numerals in parentheses are
provided purely for ease of reference and are not to be construed
as limiting features.
* * * * *